Our martial art was given the name Taekwon-Do to distinguish its techniques, philosophical system, spiritual foundation and rules of competition from other Oriental martial arts. We have a uniform unique to Taekwon-Do for the same reason.
The dobok is considered a primary necessity in both training and tournaments for the following reasons:
It is very important for the student to keep his dobok clean at all times, wear it correctly and treat it with the respect he owes to his art.
The rationale behind the plain white dobok of Japanese Karate and of Traditional Taekwon-Do, has its roots in martial tradition. One of the goals of martial arts training is to come to terms with the rather unpleasant aspect that all humans face, death. And in another sense to aid in the understanding of suffering (not that we can shed ourselves of suffering but rather to come to grips with an understanding of how our attachment to the body or "I", the universal "I", can be better understood). This is accomplished in part by attempting to abandon the ego through martial training. Freud said, "The ego is a body". And to quote martial arts author Peter Payne, "The nature of the ego, the ordinary sense of "I", is intimately bound up with the physical body".
We have a difficult time as humans extending past the egotism of the body and feeling a greater connection to the universe around us. This is evident in virtually every aspect of our life's. One of these ways is through the clothes we wear (which is, in reality, a mere extension of the body. We have physical contact with our outer garments and therefore much interconnectedness). When we put on a plain white dobok, bereft of superfluous piping and trim, we are creating an outward sign of our humility, or should I say "attempted humility". It is one very small way that bring us closer to the never obtainable perfection that is the journey in Martial Arts. As Master Hee Il Cho said, "One can go on forever developing perfection within the frame work of the Martial Arts".
Noted Ninjutsu expert Stephen Hays tells of seeing a Gi / Dobok in a Japanese museum. He attempted a joke by saying people in olden times must have been much shorter because the uniform had shorter sleeves and pant legs. If you get a pre-World War 2 martial arts book you will see this is the norm. Apparently longer sleeves and pant lengths were due to later Western influences . Anyway the host was not amused and explained that what he was seeing was really underwear, what was worn under the silk kimonos.
Apparently, the Samurai, when practicing removed the nice silken outer garments and stripped to their underwear for practice. This may have been the origins of our uniforms with the white color a natural result of heavily cleaned undergarments that had no need for colors that would also not stand up to harsh washing. This also gives an insight into training without shoes, since shoes were not worn indoors, and the slippers would have been difficult to train in.
The short sleeved kimono or "armor robe," of the samurai, was both symbolic and highly functional. According to Edwin Reischauer, former professor of Japanese history at Harvard and U.S. Ambassador to Japan from 1961 to 1966, in his book "Japan, the story of a Nation", tells us the under garment worn by the samurai was multi-purpose. On a symbolic level, the white kimono symbolized "purity and beauty in death." But the silk under garment was also a vast technological improvement over medieval western European armor.
The first stage of armor for the samurai was this silk under garment. A vast majority of fatal wounds received in battle were not from sword blows but rather from the "artillery" that was the archers. As anyone who has ever seen an arrow head knows, the end of the arrow head is flared outward with two points. The reason for this is that when the wounded party attempts to remove the arrow from their body, it literal "rips" at the surrounding flesh and organs. So the major damage from an arrow comes not from the initial piercing but from the subsequent removal.
When wearing silk, if one were to be pierced by an arrow head, it would become entangled in the tiny threads of the under garment and that would help in "dulling" the points of the arrow during removal. Thus the removal wasn't as harsh to the body.
On a side note to the rest of the armor, Japanese armor was in fact, a great advancement over western European armor. As we are aware the samurai, while engaged in very rigorous training, based their combat methods on "gentleness". The technique was similar to that of modern jujitsu (literally, the gentle art), in which flexibility of movement wins over brute strength.
The same applied to the samurai armor, which protected its wearer with flexibility and give rather than "rigid bulk". To quote Jonathan Norton Leonard, another author of Japanese history, "Unlike European armor, with its massive steel plates, Japanese armor consisted of tiny scales of lacquered iron, or lamellae, laced together in rows with silk cords. The result was a metallic fabric, as pliable as European chain mail, but considerable tougher and lighter". An entire suit of armor for a samurai weighed around 25 pounds. This is in stark contrast to the western European armor where sometimes the wearer needs the assistance of a derrick to get him on his horse.